The present invention relates in general to an apparatus for receiving polarized microwave signals. More particularly, the present invention relates to a polarized signal receiving apparatus that is adapted to effectively divide energy from a signal microwave source into two linearly polarized waves disposed in time quadrature with respect to each other.
Prior art devices that appear in this general field include devices shown in the U.S. Pat. Nos. 2,548,821; 2,742,612; 2,880,399; 3,681,714; 4,168,504; 4,414,516. Existing devices generally operate somewhat ineffectively from a mechanical standpoint and do not have the desired accuracy of mechanical rotation. Many of these devices are also quite cumbersome, such as the device illustrated in U.S. Pat. No. 2,880,399.
Accordingly, it is an object of the present invention to provide an improved apparatus for receiving polarized signals. In accordance with the preferred embodiment of the present invention, the signal coupling occurs from a circular waveguide to a rectangular waveguide with both of these waveguides being arranged with coincident axes.
Another object of the present invention is to provide an improved polarizer which is characterized by minimal reflection over a relatively wide microwave frequency band.
Still another object of the present invention is to provide a polarizer having a signal conductor or antenna for detecting polarized incoming signals in a first waveguide and for launching the detected signals into a second waveguide. Herein, the first and second waveguides are preferably circular and rectangular, respectively.
A further object of the present invention is to provide a signal conductor or antenna as set forth in the preceding object, and which may be mechanically rotated with extreme accuracy to impart rotation to the plane of polarization of energy coupled from the circular waveguide.